1. Field of the Invention
The present invention relates to thermometers and more particularly concerns electronic clinical thermometers.
2. Description of Related Information
Clinical thermometers are used primarily to measure the temperature of a living being. Temperature measurements taken orally, axillary or rectally are generally accepted as having relevance to the core temperature of the being.
Glass thermometers have been used in this fashion for many years. Glass thermometers usually include a hollow bulb containing mercury which is attached to a glass stem having a small diameter capillary extending along its length and a numerical scale. In use, as the body heat warms the mercury, the mercury expands forcing itself along the capillary. The distance the mercury travels along the capillary is related to the temperature being measured and the scale is calibrated so that the temperature is that point on the scale which is coincident with the leading edge of the mercury column in the capillary. Glass thermometers are low in cost and accurate. They are also subject to breakage, difficult for some people to read, and some users find this cold rigid shaft shaped glass instrument uncomfortable.
Attempts have been made to make the traditional glass thermometer more user friendly. For example, Blouin et al., in U.S. Pat. No. 4,072,054 teach a device consisting of a combination of a pacifier nipple structure and glass thermometer device to minimize breakage and make the temperature taking instrument more friendly to the patient which in this case would be an infant. Also, U.S. Pat. No. 2,797,682 to Kannenberg teaches a thermometer mouthpiece consisting of a flat block made of rubber, plastic or other suitable material. Kannenberg's mouthpiece includes an opening which is angularly positioned with respect to the mouthpiece for containing the known glass clinical thermometer. One of the objectives of Kannenberg's mouthpiece is to prevent biting and breaking of the thermometer. However, the temperature measurement probe in Kannenberg is still a rigid hard glass thermometer.
Sometime around the 1960's electronic thermometers began appearing in the marketplace. These thermometers usually contained a probe, a relatively large control box containing the electronics, and a wire conduit connecting the probe to the control box. The bulky mechanism and circuits, and the need for adequate electrical power made the control box a necessary separate element. U.S. Pat. No. 3,221,555 to Biber teaches a control box type thermometer. These thermometers although different from the traditional glass clinical thermometer still made little attempt for use friendliness. The probe in Biber's thermometer is made of coaxial cable with an apparently thin coating of silicone rubber.
Sometime later self contained electronic clinical thermometers appeared in the marketplace. These thermometers are a rigid assembly of a body or handle portion with a probe extending therefrom and usually include a digital display for informing the user of the temperature being measured and an on/off switch to preserve the power supply while the thermometer is not in use and/or to activate the power supply. Such thermometers are illustrated in U.S. Pat. No. Des. 254,779 to Sulek et al. and U.S. Pat. No. Des. 254,189 to Prosky.
Numerous patents teach detail improvements to the self-contained electronic clinical thermometers such as U.S. Pat. No. 4,729,672 to Takagi which teaches a structure for helping to prevent liquids from entering the interior of the thermometer. Also, U.S. Pat. No. 4,743,121 to Takagi et al. teaches a clinical thermometer case which is manufactured using multi color injection molding of a transparent window and an opaque body surrounding the window to apparently prevent liquids from entering the thermometer through the interface of the window with the case. However, little attempt has been made to improve the user friendliness of self-contained electronic thermometers which are also made of rigid hard plastic which is cold and user unfriendly.
Although the art teaches many variations of the traditional glass clinical thermometer and electronic clinical thermometers there is still a need for a simple, straight-forward, reliable, easily fabricated electronic clinical thermometer having improved user friendliness both from the standpoint of the person whose temperature is being taken and the person who is taking the temperature, and for an electronic clinical thermometer which is also more resistant to the traumas of temperature taking, such as biting and rough usage including submersion in liquid or shocks experienced by dropping the thermometer.